Safety device for blasting purposes.



I UNITED STATES PAT NT OFFI E.

JAMES M. DOYLE, or DENVER, COLORADO.

SAFETY DEVICE FOR BLASTING PURPOSES.

srncrrron'rroiv forming part of Letters Patent No. 701,173, dated May 27, 1902.

7 Application filed June 4, 1901. Serial No. 63,141. (No model.)

to others skilled in theart to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the figures of reference marked thereon, which form a part of this specification.

My invention relates to improvements in safety devices for blasting purposes, my object being to do awaylwith the danger, or at least reduce to a minimum thedanger, incident to missed shots or the failure of the powder charge to explode at theproper time.

'It is well known by those familiar with practical mining that after a hole is formed in the rock the powder charge is inserted and the cap and fuse placed-in 'position', after which the hole is tampedffullbf dirt oriany other suitable fine orgranulated material thatmay be readily accessible, the tamping material being placed in'ldirect contact with the fuse. It often happens by. reason of thecutting or 0 injury of the fuse eby the tampingmaterial or for some other :reason that the powder charge fails to explode. It then becomes necessary to remov'e'the tampingmaterial in order to put a new'fuse and capin position.

3 5 During this pickingout of the tamping materialthe concussion or jar incident to the work very frequently explodesthe charge and either kills or maims the workmen. As before intimated, my Object isto do away 40 with this danger and make it ipr'acticable to remove the old fuse and cap and insert new ones in their place, this work being quickly and easily accomplished and without danger to the workmen. 7

Having briefly'outlined theflfunction of the invention and the difficulties it is intended to overcome, I will proceed. to describe the same in detail, reference being made to the accompanying drawings, in which is illustrated an embodiment thereof.

nally, showing my improved device in place,

a closed cartridge being used. Fig. 2 is a similar section showing the device in elevation without the cartridge. Fig. 3 is an elevation' illustratmg one feature of my improved de'vicenamely, the wire forreinforcing the fuse-theparts ibeing shown on a larger. scale. In this view the ,cap is shown in sectionand crimped on the fuse. Figs. 4. and 5. illnstrate the tube' through which the fuse-is'passed,--two sections being shown.

The same reference characters indicate the sameparts in all the views.

Let the numeral 5 designate'the cap, and 6.the ifuse, both being of ordinary make or manufacture, Before placing the cap on the end of the fuse I preferably wrap a piece of fine copper wire 7 around the fuseand tie it in place. The cap is then put on and crimped. Thewireis stretched along thefuse and tied aroundit at suitable intervals to keep it in placeand strengthen or reinforce the fuse. The fuse is then threadedor passed through a tube composed of 0116101 more sections 8, according to the depth of-the hole. The sections8 are arranged-robeeasilycoupled togetherjby slipping the end'of one section over the other. In this way the lengthof the tube may beregulated at will. "This length is made sufficient to protect the fuseffromdirect contact with the atamping material the entire length of the hole. After the'powder charge is placed in the inner extremity of the hole the cap is inserted therein," leaving the fuse and its tube .or sheath projecting beyond the outer extremity of the hQle'in-the rock, the arrangement being such {that the tube is in contact withone side, preferably the bottom, of the hole. The dirt or other material is then tampedinto the hole around the tube.

In the case of a missed shot the workman immediately pulls the'fuse and cap out through the tube, the wire giving the fuse sufficient strength to prevent the possibility of its breaking or pulling apart. After the central combustible part of the fuse is consumed the latter, as a matter of oourse, is somewhat weakened, and the wire is employed to give the necessary strength to compensate for this weakness. The fuse is, however, clearly opera tive without the wire, so that it may be used or omitted at pleasure and according as circum stances or the judgment of the user may dierate. When dynamite is used for blasting purposes, no special cartridge need be employed. If black powder is used, it may be found preferable or advisable to employ a cartridge forming a suitable cylinder 10, (see Fig. 1,) composed of tin or any other suitable material, having a top 10, adapted to close the cartridge, said top being provided with a hole surrounded by a short stub-tube to which the inner extremity of the fuse-protecting tube may be fitted. The cap protruding from the inner extremity of the tube is inserted in the cartridge and the tube slipped over the stub of the top. The opening in the top and stubtube must be large enough to permit the insertion and removal of the cap. The use of the device is then the same as heretofore described when no cartridge is employed.

A so-called missed shot frequently results from the slow burning of the central portion or combustible part of the fuse. When the charge does not explode within the specified time, the workman begins to remove the tamping material. In case it is a slow fuse and the latter is still burning the charge is sometimes exploded before the tamping material is removed. WVith my improved device the cap and fuse may be immediately removed, and in case the fuse is still slowly burning no harm will be done. During the burning of the central combustible part of the-fuse the outer portion of the fuse is partially melted and expanded, whereby it fills the tube or sheath and closes the same tightly, as if the tube were not employed.

Having thus described my invention, what I claim is- 1. In a safety device for blasting purposes, the combination with a fuse and a cap attached to one extremity thereof, of a tubular open-ended sheath through which the fuse is passed-the cap being located beyond-the inner extremity of the sheath, said sheath be- 'ing of a size to fit the fuse quite closely, but

2. Thecombination with a fuse, and a cap applied to one extremity of the fuse, of a tubular open-ended sheath or conduit through which the fuse is passed, the cap being located beyond the inner extremity of the sheath which is of sufficient rigidity to maintain its form against the external pressure of the tamping material which is placed around and exterior to the sheath.

3. In a safety device for blasting purposes, the combination with a fuse and a cap attached to one extremity thereof, of a tubular open-ended sheath through which the fuse is passed, the cap being located beyond the inner extremity of the sheath, substantially as described.

4:. The combination with a cap and fuse, of a wire fastened to the cap end of the fuse, the fastening or knot in the wire being inside the cap when the latter is applied to the fuse end, the said wire being carried along the "fuse endwise and suitably connected therewith, and a tubular sheath through which the fuse and wire may be passed, and permitting the removal of the reinforced fuse and the cap, after the hole has been filled and tamped.

5. The combination with a cartridge, fuse and cap, the cartridge having an opening to receive the cap end of the fuse, and a tubular sheath for the fuse, said sheath being connected with the cartridge case, and extending the entire length of the hole'in the rock, whereby the fuse is protected and its removal together with'the cap, made practicable.

6. The combination with a fuse and a cap applied to one end thereof, of an open-ended tube through which the fuse is passed, the cap being located beyond the inner extremity of the tube which is composed of sections and constructed and arranged to protect the fuse and permit its withdrawal after the hole is filled.

In testimony whereof I affix my signature in presence of two witnesses.

JAMES M. DOYLE.

Witnesses:

A. J. OBRIEN, DORA 0. Stuart. 

